Normalize - Revision history

Reel.Deal: add link to avs+ documentation

2022-09-18T04:33:23Z

add link to avs+ documentation

Raffriff42: one more touch-up

2016-02-23T22:56:27Z

one more touch-up

Raffriff42: one more touch-up

2016-02-23T22:36:03Z

one more touch-up

Raffriff42: formatting, links, phrasing

2016-02-23T14:00:46Z

formatting, links, phrasing

Raffriff42: added category

2015-11-08T15:29:56Z

added category

Admin: 1 revision

2013-05-09T15:02:25Z

1 revision

Vdcrim: "volume" and "show" are optional parameters

2013-02-26T19:10:30Z

"volume" and "show" are optional parameters

New page

{{Template:FuncDef|Normalize(clip ''clip'' [, float ''volume''] [, bool ''show''])}}

Amplifies the entire waveform as much as possible, without clipping.

By default the clip is amplified to 1.0, that is maximum without clipping - higher values are sure to clip, and create distortions. If one volume is supplied, the other channel will be amplified the same amount.

Starting from v2.08 there is an optional argument ''show'', if set to "true", it will show the maximum amplification possible without distortions.

Stereo channels are never amplified separately by the filter, even if level between them is very different. The two volumes are applied AFTER the maximum peak has been found, and works in effect as a separate [[Amplify]]. That means if you have two channels that are very different the loudest channel will also be the peak for the lowest. If you want to normalize each channel separately, you must use [[GetChannel]] to split up the stereo source. Audio is converted to 16 bits as a side-result of this filter.

'''Examples:'''

# normalizes signal to 98%:
video = AviSource("C:\video.avi")
audio = WavSource("c:\autechre.wav")
audio = Normalize(audio, 0.98)
return AudioDub(video, audio)

# normalizes each channel separately:
video = AviSource("C:\video.avi")
audio = WavSource("bjoer7000.wav")
left_ch = GetChannel(audio,1).Normalize()
right_ch = GetChannel(audio,2).Normalize()
audio = MergeChannels(left_ch, right_ch)
return AudioDub(video, audio)

# normalizes each channel separately:
clip = AviSource("D:\Video\rawstuff\stereo-test file_left(-6db).avi")
left_ch = GetChannel(clip,1).Normalize()
right_ch = GetChannel(clip,2).Normalize()
audio = MergeChannels(left_ch, right_ch)
AudioDub(clip, audio)

[[Category:Internal filters]]

@@ Line 1: / Line 1: @@
 <div style="max-width:62em" >
 Raises (or lowers) the loudest peak of the audio track to a given {{FuncArg|volume}}. This process is called [[Wikipedia:Audio_normalization|''audio normalization'']].<br>
 Note that '''Normalize''' performs [[Wikipedia:Audio_normalization#Peak_normalization|''peak normalization'']] (used to prevent audio [[Wikipedia:Clipping_(audio)#Digital_clipping|clipping]]) and not [[Wikipedia:Audio_normalization#Loudness_normalization|loudness normalization]].

@@ Line 10: / Line 10: @@
 :{{Par2|clip |clip|}}
 ::Source clip. Supported [[ConvertAudio|audio sample types]]: 16-bit integer and [[Float|32-bit floating-point]].
-::Other sample types (8-, 24- and 32-bit integer) are converted to floating-point automatically.
+::Other sample types (8-, 24- and 32-bit integer) are automatically converted to floating-point.
 :{{Par2|volume|float|1.0}}
-::Set the amplitude of the loudest audio peak. Default = 1.0 for peaking at 0[[Wikipedia:DBFS|dB]]: for [[Float|32-bit floating-point]] audio, this corresponds to the range -1.0 to +1.0, and for for 16-bit integer audio, this this corresponds to the range -32768 to +32767 &ndash; the widest range possible without [[Wikipedia:Clipping_(audio)#Digital_clipping|clipping]].
+::Set the amplitude of the loudest audio. Default = 1.0 for peaking at 0[[Wikipedia:DBFS|dB]]: for [[Float|floating-point]] samples, this corresponds to the range -1.0 to +1.0, and for 16-bit integer samples, this corresponds to the range -32768 to +32767 &ndash; the widest range possible without [[Wikipedia:Clipping_(audio)#Digital_clipping|clipping]].
 ::*For a particular peak [[Wikipedia:Decibel|decibel]] level, use the equation {{FuncArg|volume}} = {{Serif|10}}<sup> {{Serif|'''dB''' / 20}}</sup>
 ::*For example, set a -3dB peak with {{FuncArg|volume}} = 10<sup>-3/20</sup> or 0.7079.
@@ Line 22: / Line 22: @@
 ==== ''Normalization and Floating-point Audio'' ====
-The idea of digital ''clipping'' (when the signal is outside the range that can be stored accurately) really applies only to ''integer'' sample types; floating-point values will never clip in practice, as [[Wikipedia:Single-precision_floating-point_format|their limit]] is around 3.4×10<sup>38</sup> &ndash; some 29 orders of magnitude larger than 16bit.
+The idea of digital ''clipping'' (when the signal is outside the range that can be stored accurately) really applies only to ''integer'' sample types; floating-point samples will never become clipped in practice, as [[Wikipedia:Single-precision_floating-point_format|the maximum value]] is around 3.4×10<sup>38</sup> &ndash; some 29 orders of magnitude (580 dB) larger than 16-bit samples can store.
-'''Normalize''' is therefore not needed for floating-point audio, but using it is recommended before [[ConvertAudio|converting]] to an integer type, especially if any processing has been done, such as [[Amplify|amplification]], [[MixAudio|mixing]] or [[SuperEQ|equalization]].
+'''Normalize''' is therefore not needed for floating-point audio, but using it is recommended before [[ConvertAudio|converting]] to an integer type, especially if any processing has been done &ndash; such as [[Amplify|amplification]], [[MixAudio|mixing]] or [[SuperEQ|equalization]] &ndash; which may expand the audio peaks beyond the integer clipping range.
 ==== Examples ====
@@ Line 57: / Line 57: @@
 </div>
 :[[File:NormalizeEx2_v1,0.png]]
-:(showing frame 2744, where the loudest peak was detected, but ''Amplify Factor'' is the same for all frames)
+:(showing frame 2744 where the loudest peak was detected, but note that ''Amplify Factor'' is the same for all frames)

@@ Line 1: / Line 1: @@
 <div style="max-width:62em" >
-Raises (or lowers) the loudest part of the audio track to a given {{FuncArg|volume}}, which by default is the loudest possible without [[Wikipedia:Clipping_%28audio%29|clipping]]. <br>
+Raises (or lowers) the loudest peak of the audio track to a given {{FuncArg|volume}}. This process is called [[Wikipedia:Audio_normalization|''audio normalization'']].<br>
-This process is called [[Wikipedia:Audio_normalization|''audio normalization'']].
+Note that '''Normalize''' performs [[Wikipedia:Audio_normalization#Peak_normalization|''peak normalization'']] (used to prevent audio [[Wikipedia:Clipping_(audio)#Digital_clipping|clipping]]) and not [[Wikipedia:Audio_normalization#Loudness_normalization|loudness normalization]].
 ==== Syntax and Parameters ====
@@ Line 7: / Line 7: @@
 |Normalize(clip ''clip'' [, float ''volume'' , bool ''show'' ] )
 }}
 :{{Par2|volume|float|1.0}}
-::Set the amplitude of the loudest audio peak. Default = 1.0, (or 0[[Wikipedia:DBFS|dB]], the maximum level possible without [[Wikipedia:Clipping_%28audio%29|clipping]]).
+::Set the amplitude of the loudest audio peak. Default = 1.0 for peaking at 0[[Wikipedia:DBFS|dB]]: for [[Float|32-bit floating-point]] audio, this corresponds to the range -1.0 to +1.0, and for for 16-bit integer audio, this this corresponds to the range -32768 to +32767 &ndash; the widest range possible without [[Wikipedia:Clipping_(audio)#Digital_clipping|clipping]].
-::For a particular decibel level, use the equation {{FuncArg|volume}} = {{Serif|10}}<sup> {{Serif|'''dB''' / 20}}</sup>
+::*For a particular peak [[Wikipedia:Decibel|decibel]] level, use the equation {{FuncArg|volume}} = {{Serif|10}}<sup> {{Serif|'''dB''' / 20}}</sup>
-::For example, set a -3dB peak with {{FuncArg|volume}} = 10<sup>-3/20</sup> or 0.7079.
+::*For example, set a -3dB peak with {{FuncArg|volume}} = 10<sup>-3/20</sup> or 0.7079.
-::Where multiple audio channels are present, all channel gains are set in proportion. For example, if the loudest peak on the loudest channel comes to -10dB, by default a gain of +10dB is applied to all channels.
+::*Where multiple audio channels are present, all channel gains are set in proportion. For example, if the loudest peak on the loudest channel comes to -10dB, by default a gain of +10dB is applied to all channels.
 :{{Par2|show|bool|false}}
-::If ''true'', a text overlay (see image below) will show the maximum amplification possible without distortions.
+::If ''true'', a text overlay (see image below) will show the calculated amplification factor and the frame number of the loudest peak.
 ==== Examples ====

@@ Line 1: / Line 1: @@
-{{Template:FuncDef|Normalize(clip ''clip'' [, float ''volume''] [, bool ''show''])}}
+<div style="max-width:62em" >
-Amplifies the entire waveform as much as possible, without clipping.
+==== Syntax and Parameters ====
-By default the clip is amplified to 1.0, that is maximum without clipping - higher values are sure to clip, and create distortions. If one volume is supplied, the other channel will be amplified the same amount.
+:{{Par2|volume|float|1.0}}
-Starting from v2.08 there is an optional argument ''show'', if set to "true", it will show the maximum amplification possible without distortions.
+:{{Par2|show|bool|false}}
-Stereo channels are never amplified separately by the filter, even if level between them is very different. The two volumes are applied AFTER the maximum peak has been found, and works in effect as a separate [[Amplify]]. That means if you have two channels that are very different the loudest channel will also be the peak for the lowest. If you want to normalize each channel separately, you must use [[GetChannel]] to split up the stereo source. Audio is converted to 16 bits as a side-result of this filter.
+==== Examples ====
-'''Examples:'''
+* Normalize each channel separately (eg for separate language tracks)
- # normalizes signal to 98%:
+* Effect of {{FuncArg|show}}=true with added [[Histogram]], [[Waveform]] and [[Runtime_environment#Special_runtime_variables_and_functions|current_frame]] overlays
-  video = AviSource("C:\video.avi")
+<div {{BoxWidthIndent|44|2}} >
-  audio = WavSource("c:\autechre.wav")
+  LoadPlugin(p + "[[Waveform]]\waveform.dll")
-  audio = Normalize(audio, 0.98)
+  V=[[BlankClip]](pixel_type="YV12", width=480, height=360).[[Loop]]
-  return AudioDub(video, audio)
+ A=[[WavSource]]("music.wav")
 [[Category:Internal filters]]
 [[Category:Audio_filters]]

← Older revision		Revision as of 15:29, 8 November 2015
Line 34:		Line 34:

	[[Category:Internal filters]]		[[Category:Internal filters]]
		+	[[Category:Audio_filters]]